Nevus (pl. nevi) is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa.[1] The term originates from naevus, which is Latin for "birthmark"; however, a nevus can be either congenital (present at birth) or acquired. Common terms (mole, birthmark, beauty mark, etc.) are used to describe nevi, but these terms do not distinguish specific types of nevi from one another.